With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cvpdnSessionAttrTable
cvpdn Session Attr Table
1.3.6.1.4.1.9.10.24.1.3.2
Table of information about individual sessions within the active tunnels. An entry is added to the table when a new session is initiated and removed from the table when the session is terminated.
Back to CISCO-VPDN-MGMT-MIB MIB page.
IPHost Network monitor allows you to monitor cvpdnSessionAttrTable on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco firewalls right now.